There have been repeated claims that this past year's hurricane activity was another sign of human-induced climate change. Everything from the heat wave in Paris to heavy snows in Buffalo has been blamed on people burning gasoline to fuel their cars, and coal and natural gas to heat, cool and electrify their homes. Yet how can a barely discernible, one-degree increase in the recorded global mean temperature since the late 19th century possibly gain public acceptance as the source of recent weather catastrophes? And how can it translate into unlikely claims about future catastrophes?

The answer has much to do with misunderstanding the science of climate, plus a willingness to debase climate science into a triangle of alarmism. Ambiguous scientific statements about climate are hyped by those with a vested interest in alarm, thus raising the political stakes for policy makers who provide funds for more science research to feed more alarm to increase the political stakes. After all, who puts money into science--whether for AIDS, or space, or climate--where there is nothing really alarming?

Indeed, the success of climate alarmism can be counted in the increased federal spending on climate research from a few hundred million dollars pre-1990 to $1.7 billion today. It can also be seen in heightened spending on solar, wind, hydrogen, ethanol and clean coal technologies, as well as on other energy-investment decisions.

But there is a more sinister side to this feeding frenzy. Scientists who dissent from the alarmism have seen their grant funds disappear, their work derided, and themselves libeled as industry stooges, scientific hacks or worse. Consequently, lies about climate change gain credence even when they fly in the face of the science that supposedly is their basis.

To understand the misconceptions perpetuated about climate science and the climate of intimidation, one needs to grasp some of the complex underlying scientific issues. First, let's start where there is agreement. The public, press and policy makers have been repeatedly told that three claims have widespread scientific support: Global temperature has risen about a degree since the late 19th century; levels of CO2 in the atmosphere have increased by about 30% over the same period; and CO2 should contribute to future warming.

These claims are true. However, what the public fails to grasp is that the claims neither constitute support for alarm nor establish man's responsibility for the small amount of warming that has occurred. In fact, those who make the most outlandish claims of alarm are actually demonstrating skepticism of the very science they say supports them. It isn't just that the alarmists are trumpeting model results that we know must be wrong. It is that they are trumpeting catastrophes that couldn't happen even if the models were right as justifying costly policies to try to prevent global warming.

If the models are correct, global warming reduces the temperature differences between the poles and the equator. When you have less difference in temperature, you have less excitation of extratropical storms, not more. And, in fact, model runs support this conclusion. Alarmists have drawn some support for increased claims of tropical storminess from a casual claim by Sir John Houghton of the U.N.'s Intergovernmental Panel on Climate Change (IPCC) that a warmer world would have more evaporation, with latent heat providing more energy for disturbances.

The problem with this is that the ability of evaporation to drive tropical storms relies not only on temperature but humidity as well, and calls for drier, less humid air. Claims for starkly higher temperatures are based upon there being more humidity, not less--hardly a case for more storminess with global warming.

So how is it that we don't have more scientists speaking up about this junk science? It's my belief that many scientists have been cowed not merely by money but by fear. An example: Earlier this year, Texas Rep. Joe Barton issued letters to paleoclimatologist Michael Mann and some of his co-authors seeking the details behind a taxpayer-funded analysis that claimed the 1990s were likely the warmest decade and 1998 the warmest year in the last millennium.

Mr. Barton's concern was based on the fact that the IPCC had singled out Mr. Mann's work as a means to encourage policy makers to take action. And they did so before his work could be replicated and tested--a task made difficult because Mr. Mann, a key IPCC author, had refused to release the details for analysis. The scientific community's defense of Mr. Mann was, nonetheless, immediate and harsh. The president of the National Academy of Sciences--as well as the American Meteorological Society and the American Geophysical Union--formally protested, saying that Rep. Barton's singling out of a scientist's work smacked of intimidation.

All of which starkly contrasts to the silence of the scientific community when anti-alarmists were in the crosshairs of then-Sen. Al Gore. In 1992, he ran two congressional hearings during which he tried to bully dissenting scientists, including myself, into changing our views and supporting his climate alarmism. Nor did the scientific community complain when Mr. Gore, as vice president, tried to enlist Ted Koppel in a witch hunt to discredit anti-alarmist scientists--a request that Mr. Koppel deemed publicly inappropriate. And they were mum when subsequent articles and books by Ross Gelbspan libelously labeled scientists who differed with Mr. Gore as stooges of the fossil-fuel industry.

Sadly, this is only the tip of a non-melting iceberg. In Europe, Henk Tennekes was dismissed as research director of the Royal Dutch Meteorological Society after questioning the scientific underpinnings of global warming. Aksel Winn-Nielsen, former director of the U.N.'s World Meteorological Organization, was tarred by Bert Bolin, first head of the IPCC, as a tool of the coal industry for questioning climate alarmism. Respected Italian professors Alfonso Sutera and Antonio Speranza disappeared from the debate in 1991, apparently losing climate-research funding for raising questions.

And then there are the peculiar standards in place in scientific journals for articles submitted by those who raise questions about accepted climate wisdom. At Science and Nature, such papers are commonly refused without review as being without interest. However, even when such papers are published, standards shift.

When I, with some colleagues at NASA, attempted to determine how clouds behave under varying temperatures, we discovered what we called an "Iris Effect," wherein upper-level cirrus clouds contracted with increased temperature, providing a very strong negative climate feedback sufficient to greatly reduce the response to increasing CO2. Normally, criticism of papers appears in the form of letters to the journal to which the original authors can respond immediately.

However, in this case (and others) a flurry of hastily prepared papers appeared, claiming errors in our study, with our responses delayed months and longer. The delay permitted our paper to be commonly referred to as "discredited." Indeed, there is a strange reluctance to actually find out how climate really behaves. In 2003, when the draft of the U.S. National Climate Plan urged a high priority for improving our knowledge of climate sensitivity, the National Research Council instead urged support to look at the impacts of the warming--not whether it would actually happen.

Alarm rather than genuine scientific curiosity, it appears, is essential to maintaining funding. And only the most senior scientists today can stand up against this alarmist gale, and defy the iron triangle of climate scientists, advocates and policymakers.Mr. Lindzen is Alfred P. Sloan Professor of Atmospheric Science at MIT.